The application of the diabetes prevention trial-type 1 risk score for identifying a preclinical state of type 1 diabetes.

OBJECTIVE-We assessed the utility of the Diabetes Prevention Trial Type 1 Risk Score (DPTRS) for identifying individuals who are highly likely to progress to type 1 diabetes (T ID) within 2 years. RESEARCH DESIGN AND METHODS-The DPTRS was previously developed from Diabetes Prevention Trial Type 1 (DPT-1) data and was subsequently validated in the TrialNet Natural History Study (TNNHS). DPTRS components included C-peptide and glucose indexes from oral glucose tolerance testing, along with age and BM1. The cumulative incidence of T ID was determined after DPTRS thresholds were first exceeded and after the first occurrences of glucose abnormalities. RESULTS-The 2-year risks after the 9.00 DPTRS threshold was exceeded were 0.88 and 0.77 in DPT-1 (n = 90) and the TNNHS (n = 69), respectively. In DPT-1, the 2-year risks were much lower after dysglycemia first occurred (0.37; n = 306) and after a 2-h glucose value between 190 and 199 mg/dL was first reached (0.64; n = 59). Among those who developed T1D in DPT-1, the 9.00 threshold was exceeded 0.81 +/- 0.53 years prior to the conventional diagnosis. Post-challenge C-peptide levels were substantially higher (P = 0.001 for 30 min; P < 0.001 for other time points) when the 9.00 threshold was first exceeded compared with the levels at diagnosis. CONCLUSIONS-A DPTRS threshold of 9.00 identifies individuals who are very highly likely to progress to the conventional diagnosis of T ID within 2 years and, thus, are essentially in a preclinical diabetic state. The 9.00 threshold is exceeded well before diagnosis, when stimulated C-peptide levels are substantially higher. Diabetes Care 35:1552-1555,2012